The aim of this paper is to explore whether and how the Five-Factor Model (FFM) of personality - also known as the Big Five - may be relevant to psychology of religion. First, we review empirical research which has used Eysenck's taxonomy. Second, after a brief presentation of the FFM, we hypothesize, on the basis of research in the Eysenck framework as well as on the basis of research in psychology of religion generally, how each of the five factors may be related to religiosity. Third, we insist on the necessity of including gender differences when studying the association between personality and religion. Fourth, we discuss the results from an exploratory study on religiousness and the FFM (Saroglou, 1998) and we compare the results of this study with the few studies on Big Five to have used religious variables. Finally, the discussion focuses on the importance of personality taxonomies when studying religiosity and on the usefulness of the FFM for this purpose.